Ion generator and air conditioner

ABSTRACT

In order to efficiently kill airborne fungi in a room, an ion generator includes an ion generator, a temperature sensor for detecting a temperature, and a humidity sensor for detecting a humidity. The ion generator is controlled based on a temperature detection result detected by the temperature sensor and a humidity detection result detected by the humidity sensor. As ions are generated in accordance with the temperature and humidity, airborne fungi can efficiently be killed.

TECHNICAL FIELD

The present invention relates to an ion generator and an airconditioning apparatus, and more particularly to an ion generator and anair conditioning apparatus for sterilizing air in a room.

BACKGROUND ART

An ion generator ionizing vapor present in a space has conventionallybeen known. Some of the ion generators employ creeping discharge. In theconventional ion generator, when an alternating voltage is applied to anion generating element, positive ions and negative ions are generated.It is known that these generated positive and negative ions eliminatemolds, airborne fungi or viruses in the air.

Japanese Patent Laying-Open No. 2003-83593 discloses a technique toapply such an ion generator to an air conditioner so as to suppressmolds. The air conditioner disclosed in Japanese Patent Laying-Open No.2003-83593 generates positive and negative ions from the ion generator,and determines whether or not dehumidification or cooling/heating shouldbe performed in accordance with detected temperature or humidity in theroom.

The air conditioner disclosed in Japanese Patent Laying-Open No.2003-83593 generates positive and negative ions from the ion generatorwhenever it is driven. Therefore, the air conditioner generates aconstant amount of positive and negative ions regardless of thetemperature or humidity in the room. In other words, a prescribed amountof power is consumed in order to generate positive and negative ions.

In general, it is known that molds tend to grow in an environment ofhigh temperature and high humidity. As to viruses, it is also known thatinfluenza virus attains high survival ratio at low temperature and lowhumidity. Accordingly, concentration of the positive and negative ionsin the air does not need to be high in an environment in which fungisuch as molds or influenza viruses are less likely to proliferate.

Furthermore, it is known that an atmosphere containing a large amount ofnegative ions provides a comfortable environment for humans, with arefreshing effect. On the other hand, it is impossible to simultaneouslyrealize a state in which a large amount of both positive and negativeions is present and a state in which a large amount of negative ions ispresent in a room.

DISCLOSURE OF THE INVENTION

The present invention was made to solve the above-described problems. Anobject of the present invention is to provide an ion generator capableof efficiently killing airborne fungi in a room.

Another object of the present invention is to provide an ion generatorcapable of preventing proliferation of molds or influenza viruses.

Yet another object of the present invention is to provide an iongenerator consuming less power.

Yet another object of the present invention is to provide an iongenerator capable of killing airborne fungi in the room and creating anenvironment comfortable for humans.

Yet another object of the present invention is to provide an airconditioning apparatus capable of efficiently killing airborne fungi.

In order to achieve the above-described objects, according to one aspectof the present invention, an ion generator includes ion generationmeans, temperature detection means for detecting a temperature, andhumidity detection means for detecting a humidity. The ion generationmeans is controlled based on a temperature detection result detected bythe temperature detection means and a humidity detection result detectedby the humidity detection means.

According to the present invention, the ion generation means iscontrolled based on the temperature detection result and the humiditydetection result. As ions are generated in accordance with thetemperature and the humidity, the ion generator capable of efficientlykilling airborne fungi can be provided.

Preferably, the ion generator further includes state notification meansfor notification of the temperature detection result and/or the humiditydetection result, and instruction accepting means for accepting aninstruction to start control of the ion generation means. Control of theion generation means is started in response to acceptance of theinstruction by the instruction accepting means.

According to the present invention, control of the ion generation meansis started in response to acceptance of the instruction by theinstruction accepting means. Therefore, the ion generation means can becontrolled when a user desires.

Preferably, control of the ion generation means refers to control of anamount of ion generation.

According to the present invention, ions in an amount in accordance withthe temperature and the humidity are generated. Therefore, the iongenerator capable of efficiently killing airborne fungi can be provided.

According to another aspect of the present invention, an ion generatorincludes ion generation means for generating ions, temperature andhumidity detection means for detecting a temperature and a humidity in aroom, and control means for controlling the ion generation means so asto generate a larger amount of ions than in a normal state, when a stateof the room detected by the temperature and humidity detection meansattains a prescribed state.

According to the present invention, when the state of the room attainsthe prescribed state, ions in an amount larger than that in a normalstate are generated from the ion generation means. The ions areeffective in killing fungi floating in the air. Assuming that theprescribed state here refers to a state in which airborne fungi arelikely to proliferate, the ion generator capable of efficiently killingairborne fungi can be provided.

In addition, when the room is not in the prescribed state, ions in anamount comparable to that in the normal state are generated by the iongeneration means. Therefore, the airborne fungi can be killed even inthe normal state. Moreover, as the larger amount of ions is generated,power supplied to the ion generation means increases. As the ions aregenerated with low power consumption in the normal state, powerconsumption can be minimized. As a result, the ion generator consumingless power can be provided.

Preferably, the ion generation means generates positive ions andnegative ions.

Preferably, the prescribed state includes a first state in which moldsare likely to proliferate.

According to the present invention, in the first state in which moldsare likely to proliferate, ions in an amount larger than in the normalstate are generated. The ions are effective in killing fungi floating inthe air. Therefore, the ion generator capable of preventingproliferation of molds in the first state in which molds are likely toproliferate can be provided.

Preferably, the prescribed state is characterized in that thetemperature detected by the temperature detection means is at least 25°C. and the humidity detected by the humidity detection means is at least70%.

Preferably, the prescribed state includes a second state in whichviruses are likely to proliferate.

According to the present invention, in the second state in which virusesare likely to proliferate, ions in an amount larger than in the normalstate are generated. Therefore, the ion generator capable of preventingproliferation of viruses in the second state in which viruses are likelyto proliferate can be provided.

Preferably, the ion generator further includes impureness detectionmeans for detecting impureness in the room. The control means causes theion generation means to generate negative ions more than positive ions,when a state of the room detected by the temperature and humiditydetection means does not attain the prescribed state and when aprescribed degree of impureness is not detected by the impurenessdetection means.

According to the present invention, when the state of the room does notattain the prescribed state and when the prescribed degree of impurenessis not detected, negative ions more than positive ions are generated.When negative ions are contained in the air in an amount larger thanthat of positive ions, refreshing effect for humans can be obtained.Therefore, the ion generator capable of creating an environmentcomfortable for humans, for example, when the room is clean and not inan environment in which airborne fungi are likely to proliferate can beprovided.

Preferably, the impureness detection means includes a dust sensor.

Preferably, the impureness detection means includes an odor sensor.

According to another aspect of the present invention, an ion generatorincludes: ion generation means for generating ions; impureness detectionmeans for detecting impureness in a room; and temperature and humiditydetection means for detecting a temperature and a humidity in the room.An amount of ions generated by the ion generation means is controlledwhen a state of the room detected by the impureness detection means andthe temperature and humidity detection means attains a prescribed state.

According to the present invention, when the state of the room detectedby the impureness detection means and the temperature and humiditydetection means attains the prescribed state, an amount of ionsgenerated by the ion generation means is controlled. When the air isimpure, it is probable that airborne fungi are contained. If an amountof ion generation is increased when the air in the room is impure andthe room is in an environment where airborne fungi are likely toproliferate, proliferation of the airborne fungi can efficiently beprevented.

Preferably, the prescribed state includes a first state at a temperatureand a humidity equal to or higher than a first temperature and a firsthumidity respectively, and a second state at a temperature and ahumidity equal to or lower than a second temperature and a secondhumidity respectively. Here, the second temperature is lower than thefirst temperature and the second humidity is lower than the firsthumidity.

According to the present invention, when the room is in the first stateat a temperature and a humidity equal to or higher than the firsttemperature and the first humidity respectively or in the second stateat a temperature and a humidity equal to or lower than the secondtemperature and the second humidity respectively, an amount of generatedpositive and negative ions is increased. The positive and negative ionsare effective in killing fungi floating in the air. Therefore, if thefirst state is assumed as an environment where molds are likely toproliferate and the second state is assumed as an environment whereinfluenza viruses are likely to proliferate, the ion generator capableof preventing-proliferation of molds or influenza viruses can beprovided.

Preferably, the control means causes the ion generation means togenerate negative ions more than positive ions, when a degree ofimpureness detected by the impureness detection means does not attain aprescribed value and when a state of the room detected by thetemperature and humidity detection means does not attain the prescribedstate.

According to the present invention, when the degree of impureness doesnot attain the prescribed value and when the state of the room does notattain the prescribed state, negative ions are generated in an amountlarger than that of positive ions. When negative ions are contained inthe air in an amount larger than that of positive ions, refreshingeffect can be obtained. Therefore, when there is smaller amount ofairborne fungi in the room and an environment is such that fungi areunlikely to proliferate, an environment comfortable for humans can becreated.

Preferably, the impureness detection means includes a dust sensor.

Preferably, the impureness detection means includes an odor sensor.

According to another aspect of the present invention, an airconditioning apparatus includes cleaning means for lowering a degree ofimpureness in a room, and the ion generator described above.

According to the present invention, as impureness in the room islowered, an environment in which airborne fungi are less likely toproliferate can be created. Therefore, an air conditioning apparatuscapable of efficiently killing the airborne fungi can be provided.

According to yet another aspect of the present invention, an airconditioning apparatus includes dehumidifying and humidifying means foradjusting a humidity in a room, and the ion generator described above.

According to the present invention, as the humidity in the room isadjusted, an environment in which airborne fungi are less likely toproliferate can be created. Therefore, an air conditioning apparatuscapable of efficiently killing the airborne fungi can be provided.

According to yet another aspect of the present invention, an airconditioning apparatus includes cooling and heating means for adjustinga temperature in a room, and the ion generator described above.

According to the present invention, as the temperature in the room isadjusted, an environment in which airborne fungi are less likely toproliferate can be created. Therefore, an air conditioning apparatuscapable of efficiently killing the airborne fungi can be provided.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a front view of an air conditioning apparatus in a firstembodiment of the present invention.

FIG. 1B is a plan view of the air conditioning apparatus in the firstembodiment of the present invention.

FIG. 2 is a cross-sectional view along the line II-II in FIG. 1A.

FIG. 3 illustrates a display portion of the air conditioning apparatusin the first embodiment.

FIG. 4 shows a relation between an operation mode of the airconditioning apparatus and display contents on the display portion inthe first embodiment.

FIG. 5 is a plan view of a remote controller of the air conditioningapparatus in the first embodiment.

FIG. 6 is a circuit block diagram of the air conditioning apparatus inthe first embodiment.

FIG. 7A is a plan view schematically showing a configuration of an iongenerator in the first embodiment.

FIG. 7B is a side view schematically showing the configuration of theion generator in the first embodiment.

FIG. 8 is a circuit diagram of a voltage application circuit in thefirst embodiment.

FIG. 9A is a diagram illustrating a voltage pulse output from thevoltage application circuit in the first embodiment.

FIG. 9B is another diagram illustrating a voltage pulse output from thevoltage application circuit in the first embodiment.

FIG. 10 is a circuit diagram of a voltage application circuit in avariation of the first embodiment.

FIG. 11A is a diagram illustrating a voltage pulse output from thevoltage application circuit in the variation.

FIG. 11B is another diagram illustrating a voltage pulse output from thevoltage application circuit in the variation.

FIG. 12A shows a variation of the ion generator in the first embodiment.

FIG. 12B shows another variation of the ion generator in the firstembodiment.

FIG. 13 is a circuit diagram of a voltage application circuit connectedto the ion generator in the variation.

FIG. 14 shows an example of a degree of impureness evaluation table usedin the air conditioning apparatus in the first embodiment.

FIG. 15 is a flowchart illustrating a flow of an operation modedetermining process executed in the air conditioning apparatus in thefirst embodiment.

FIG. 16 shows a relation between an operation mode for air-conditioningand a fan motor output and a voltage applied to the ion generator in thefirst embodiment.

FIG. 17 shows one example of a prescribed state.

FIG. 18A is a front view showing appearance of an air conditioningapparatus in a second embodiment.

FIG. 18B is a plan view showing appearance of the air conditioningapparatus in the second embodiment.

FIG. 19 is a flowchart illustrating a flow of an operation modedetermining process executed in the air conditioning apparatus in thesecond embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

In the following, embodiments of the present invention will be describedwith reference to the figures. It is noted that the same referencecharacters refer to the same or corresponding components and denotationand functions thereof are also the same. Therefore, detailed descriptionthereof will not be repeated.

First Embodiment

Initially, an air conditioning apparatus in the first embodiment will bedescribed. FIGS. 1A and 1B show appearance of an air conditioningapparatus in one embodiment of the present invention. FIG. 1A shows afront view, while FIG. 1B shows a plan view. Referring to FIGS. 1A and1B, an air conditioning apparatus 100 includes a front panel 101 on afront face of a main unit 110. Front panel 101 is attached with aprescribed space in front of main unit 110 for air intake. Front panel101 has an opening for taking the air into main unit 110 in the center.

In the rear of the opening of front panel 101, a central panel 102 isattached to main unit 110. As front panel 101 and central panel 102block the view, an inner portion of the main unit cannot be seen fromthe front. A display portion 103 is provided in an upper portion offront panel 101. Display portion 103 also includes an upper portion ofcentral panel 102.

A top panel 104 is provided on the top of main unit 110. Top panel 104includes a power switch 106. In addition, top panel 104 includes anoutlet 105 for emitting purified air.

Air conditioning apparatus 100 includes a temperature sensor 151, ahumidity sensor 152, a dust sensor 153, and an odor sensor 154 in mainunit 110 behind front panel 101.

FIG. 2 is a cross-sectional view along the line II-II in. FIG. 1A. It isnoted that arrows in the drawing indicate flow of the air. Referring toFIG. 2, air conditioning apparatus 100 includes temperature sensor 151,humidity sensor 152, dust sensor 153, and odor sensor 154 in main unit110. Front panel 101 is attached to main unit 110 with a gap for airintake. This gap serves as an air inlet. In addition, central panel 102is attached to main unit 110 in the rear of the opening in the center offront panel 101. This opening also serves as an air inlet for taking theair in the room into the main unit 110.

An ion generator 10 is provided in main unit 110 under top panel 104.Though not shown, an air purifying filter for purifying the air and afan motor and a fan for flowing the air are further provided between theair inlet and outlet 105.

Air conditioning apparatus 100 drives the contained fan motor so as torotate the fan and so as to generate air flow. The air flow is directedfrom the air inlet toward outlet 105. In this manner, the air isintroduced from the air inlet into main unit 110, and carried totemperature sensor 151, humidity sensor 152, dust sensor 153, and odorsensor 154. Further, the air passes through a deodorizing filter toreach outlet 105, from which the air is discharged to the room. As iongenerator 10 is provided between the deodorizing filter and outlet 105,the air is ionized when the air flows in the vicinity of ion generator10. Therefore, the air exiting from outlet 105 contains ions.

In air conditioning apparatus 100 in the present embodiment, temperaturesensor 151, humidity sensor 152, dust sensor 153, and odor sensor 154are provided in the vicinity of the air inlet. Therefore, roomtemperature and humidity as well as an amount of dust and odor canaccurately be detected.

It is noted that attachment positions of temperature sensor 151,humidity sensor 152, dust sensor 153, and odor sensor 154 are notlimited to the above-mentioned example. Such positions are not limited,so long as those sensors are located around the air inlet in airconditioning apparatus 100.

FIG. 3 illustrates the display portion of the air conditioning apparatusin the first embodiment. Referring to FIG. 3, display portion 103includes a light receiving portion 111 for receiving an infrared rayfrom a remote controller for remote control of air conditioningapparatus 100; a deodorizing filter cleaning indicator light 112 fornotifying a user of a time to clean the deodorizing filter provided inair conditioning apparatus 100; a prediction purification indicatorlight 113 indicating whether or not an operation mode of airconditioning apparatus 100 is set to a prediction purification mode; aclean sign indicator light 114 indicating a degree of impureness of theair in the room; a cluster ion indicator light 115 indicating a drivemode of ion generator 10; an automatic operation indicator light 116, aquick mode indicator light 117 and a pollen mode indicator light 118 forindicating an operation mode of air conditioning apparatus 100; threemanual state indicator lights 119 indicating a drive state of the fanmotor when the operation mode is set to a manual mode; and an off timerindicator light 120 indicating an off-timer setting time.

Deodorizing filter cleaning indicator light 112 illuminates when a valuefor accumulated operation time of air conditioning apparatus 100 exceedsa predetermined deodorizing filter cleaning time, and otherwise it turnsoff. In this manner, the user can be notified of a timing to clean thedeodorizing filter in air conditioning apparatus 100.

Operation modes of air conditioning apparatus 100 include an automaticmode, a quick mode, a pollen mode, and a manual mode. The automaticoperation mode refers to an operation mode in which the fan level of thefan motor and an amount of ion generation by ion generator 10 areautomatically controlled in accordance with a degree of impurenessdetermined by outputs from dust sensor 153 and odor sensor 154. When airconditioning apparatus 100 operates in the automatic operation mode,automatic operation indicator light 116 illuminates. The quick moderefers to an operation mode in which the fan motor and ion generator 10operate at maximum power. When air conditioning apparatus 100 operatesin the quick mode, quick mode indicator light 117 illuminates. Thepollen mode refers to an operation mode in which the fan motor and theion generator are driven so as to attain output suitable for eliminatingpollens. The outputs of the fan motor and ion generator 10 suitable foreliminating pollens are predetermined and stored. When air conditioningapparatus 100 operates in the pollen mode, pollen mode indicator light118 illuminates. The manual mode refers to an operation mode in whichthe fan motor and ion generator 10 are driven so as to attain outputdesignated by the user. When air conditioning apparatus 100 operates inthe manual mode, any one of three manual state indicators 119 indicatinga drive state of the fan motor of silent, medium and maximum illuminatesin accordance with the output designated by the user. As to iongenerator 10, cluster ion indicator light 115 illuminates in a colordescribed later, in accordance with the output designated by the user.

Off timer indicator light 120 indicates a timer setting time designatedby the user. Any one of three off timer indicator lights 120illuminates.

Clean sign indicator light 114 indicates a degree of impureness of theair in the room. In the present embodiment, three levels of the degreeof impureness are set. The degree of impureness is determined by outputsfrom dust sensor 153 and odor sensor 154. Clean sign indicator light 114illuminates in green, orange or red, in accordance with the degree ofimpureness. Clean sign indicator light 114 illuminates in green,corresponding to “0” degree of impureness indicating the lowestimpureness level; it illuminates in orange, corresponding to “1” degreeof impureness indicating an intermediate level of impureness; and itilluminates in red, corresponding to “2” degree of impureness indicatingthe highest impureness level.

Cluster ion indicator light 115 indicates a drive mode of ion generator10. Drive modes of ion generator 10 include an ion control mode and aclean mode. The ion control mode refers to a mode in which negative ionsin an amount larger than that of positive ions are generated from iongenerator 10, or to a mode in which solely negative ions are generated.The clean mode refers to a mode in which positive ions and negative ionsare generated in substantially the same amount from ion generator 10,respectively. Cluster ion indicator light 115 illuminates in green whenion generator 10 operates in the ion control mode, while it illuminatesin blue when ion generator 10 operates in the clean mode. When iongenerator 10 is not driven, cluster ion indicator light 115 turns off.

The operation mode of air conditioning apparatus 100 further includes aprediction purification mode. The prediction purification mode refers toan operation mode when the temperature and the humidity in the roomattain a prescribed state. Here, the prescribed state refers to a firststate in which the temperature is at least 25° C and the humidity is atleast 70%, or a second state in which the temperature is at most 18° C.and the humidity is at most 40%. Prediction purification indicator light113 indicates whether or not air conditioning apparatus 100 operates inthe prediction purification mode, that is, whether or not the air in theroom is in the prescribed state. Prediction purification indicator light113 illuminates when air conditioning apparatus 100 operates in theprediction purification mode, and otherwise it turns off.

When air conditioning apparatus 100 operates in the predictionpurification mode, ion generator 10 is driven in the clean mode. Here,an amount of generation of positive and negative ions is increased, ascompared with when air conditioning apparatus 100 is not in theprediction purification mode. When air conditioning apparatus 100 is notin the prediction purification mode, it is in a normal state. In otherwords, in the prediction purification mode, ion generator 10 is drivenand controlled so as to generate ions in an amount larger than that inthe normal state. This will be described in detail later.

FIG. 4 shows a relation between the operation mode of air conditioningapparatus 100 and display contents on display portion 103 in the firstembodiment. Referring to FIG. 4, when the prediction purificationindicator light turns off, clean sign indicator light 114 illuminates ineither green, orange or red, in accordance with the degree ofimpureness. Here, it takes a prescribed time from turn-on of powerswitch 106 of air conditioning apparatus 100 until outputs from dustsensor 153 and odor sensor 154 are stabilized. The degree of impurenessis not determined during a period from turn-on of the power until theoutputs from dust sensor 153 and odor sensor 154 are stabilized.Therefore, during such a time period, clean sign indicator light 114sequentially illuminates in an order of green, orange and red each forone second. Therefore, if the user observes the sequential illuminationof clean sign indicator light 114 in different colors, the user can knowthat the degree of impureness is not yet detected.

When the degree of impureness is determined as “0”, ion generator 10 isdriven in the ion control mode. Accordingly, cluster ion indicator light115 illuminates in green. In addition, when the degree of impureness isdetermined as either “1” or “2”, ion generator 10 is driven in the cleanmode. Here, cluster ion indicator light 115 illuminates in blue. Duringa prescribed time period until the degree of impureness is found, theion generator is driven in the clean mode, during which cluster ionindicator light 115 illuminates in blue.

When prediction purification indicator light 113. illuminates, cleansign indicator light 114 illuminates in accordance with the degree ofimpureness, in a manner similar to that when prediction purificationindicator light 113 turns off. On the other hand, in the predictionpurification mode, ion generator 10 is driven in the clean mode. In theclean mode, the ion generator is driven such that positive and negativeions in an amount larger than when not in the prediction purificationmode are generated. Even in such a case, cluster ion indicator light 115illuminates in blue. Therefore, if cluster ion indicator light 115illuminates in blue and prediction purification indicator light 113illuminates, the operation mode of ion generator 10 is in the cleanmode. In the clean mode, ion generator 10 generates positive andnegative ions in an amount larger than when not in the predictionpurification mode.

FIG. 5 is a plan view of remote controller 130 of air conditioningapparatus 100 in the first embodiment. Remote controller 130 includes apower switch 106A for switching on/off of the power of air conditioningapparatus 100; a filter reset button 129 for resetting accumulatedoperation time after cleaning the deodorizing filter; an automaticbutton 116A for setting the operation mode of air conditioning apparatus100 to the automatic mode; a fan level button 119A for switching to themanual mode and designating a fan level of the fan motor; a pollenbutton 118A for setting the pollen mode; an off-timer button 122A forsetting an off-timer setting time; a daily mode button 121 for setting adaily mode; a sleep automatic button 122 for setting a sleep automaticmode; a quick button 123 for setting the quick mode; a display switchbutton 124 for switching on/off of display on display portion 103; andsetting buttons 125 to 128 for manually setting the drive mode of iongenerator 10.

Remote controller 130 outputs a signal of infrared light in accordancewith the pressed switch. When light receiving portion 111 in airconditioning apparatus 100 receives the signal of infrared light, airconditioning apparatus 100 is driven in response to the signal ofinfrared light.

Though remote controller 130 using the infrared light is exemplarilydescribed in the first embodiment, a communication medium between remotecontroller 130 and air conditioning apparatus 100 is not limited to theinfrared light. For example, an electromagnetic wave or an acoustic wavecan be employed. That is, any means allowing radio communication may beused, without limited to the infrared light.

When automatic button 116A is pressed, air conditioning apparatus 100sets the operation mode to the automatic mode and operates. When fanlevel button 119A is pressed, air conditioning apparatus 100 changes thenumber of revolution of the fan motor, i.e., the fan level, in the orderof silent, medium and maximum, every time fan level button 119A ispressed. When pollen button 118A is pressed, air conditioning apparatus100 sets the operation mode to the pollen mode and operates. Every timethe off-timer button 122A is pressed, the off-timer setting time issequentially set in the order of 1 hour, 4 hours and 8 hours.

When daily mode button 121 is pressed, air conditioning apparatus 100sets the operation mode to the daily mode and operates. When sleepautomatic mode button 122 is pressed, air conditioning apparatus 100sets the number of revolution of the fan motor to the number adapted tothe silent mode.

When quick button 123 is pressed, air conditioning apparatus 100 setsthe operation mode to the quick mode and operates.

When any of setting buttons 125 to 128 is pressed, the drive mode of iongenerator 10 is switched. When setting button 126 is pressed,application of a voltage to ion generator 10 is stopped so as to stopdrive of ion generator 10. In air conditioning apparatus 100, clusterion indicator light 115 turns off. When setting button 125 is pressed,ion generator 10 is driven in the clean mode. In air conditioningapparatus 100, cluster ion indicator light 115 illuminates in blue.

When setting button 127 is pressed, ion generator 10 is driven in theion control mode in air conditioning apparatus 100, and cluster ionindicator light 115 illuminates in green.

When setting button 128 is pressed, air conditioning apparatus 100drives ion generator 10 in the automatic mode. Here, the automatic modeis determined based on outputs from temperature sensor 151, humiditysensor 152, dust sensor 153, and odor sensor 154. Control over the drivestate of ion generator 10 in the automatic mode will be described indetail later.

FIG. 6 is a circuit block diagram of air conditioning apparatus 100 inthe first embodiment. Referring to FIG. 6, ion generator 10 includes acontrol unit 150 for overall control of ion generator 10; temperaturesensor 151 for detecting a temperature, humidity sensor 152 fordetecting a humidity, dust sensor 153 for detecting dust, and odorsensor 154 for detecting odor, each of which is connected to controlunit 150; temperature setting means 155 for setting a temperature;humidity setting means 156 for setting a humidity; and a voltage drivingcircuit 20 for applying a voltage to ion generator 10. Ion generator 10is connected to voltage driving circuit 20.

As described above, air conditioning apparatus 100 includes theprediction purification mode as the operation mode. The predictionpurification mode refers to the operation mode set when the temperatureand the humidity in the room attain the prescribed state. Temperaturesetting means 155 and humidity setting means 156 are means for settingthreshold values for determining the prescribed state. Temperaturesetting means 155 and humidity setting means 156 are implemented by abutton switch or a slide switch provided in main unit 110 and serve toset the temperature and the humidity. Temperature setting means 155 andhumidity setting means 156 may be provided in remote controller 130 sothat the set temperature and humidity are transmitted from remotecontroller 130 to air conditioning apparatus 100.

FIGS. 7A and 7B schematically show a configuration of the ion generatorin the first embodiment. FIG. 7A is a plan view schematically showingthe configuration of ion generator 10, while FIG. 7B is a side view ofion generator 10. Ion generator 10 includes a dielectric 11, a dischargeelectrode 12 a, an induction electrode 12 b, and a coating layer 13.When a voltage is applied to discharge electrode 12 a and inductionelectrode 12 b, discharge occurs between discharge electrode 12 a andinduction electrode 12 b, whereby both positive and negative ions ornegative ions are generated.

Dielectric 11 is implemented as a plate-like component formed bylaminating an upper dielectric 11 a and a lower dielectric 11 b.Discharge electrode 12 a is formed integrally with upper dielectric 11 aon the surface of upper dielectric 11 a. Induction electrode 12 b isformed between upper dielectric 11 a and lower dielectric 11 b, andarranged facing to discharge electrode 12 a. Desirably, insulationresistance between discharge electrode 12 a and induction electrode 12 bis uniform, and discharge electrode 12 a is parallel to inductionelectrode 12 b.

In ion generator 10, discharge electrode 12 a and induction electrode 12b are arranged opposing to each other, on a surface and a back surfaceof upper dielectric 11 a respectively. Accordingly, a distance betweendischarge electrode 12 a and induction electrode 12 b can be constant.In this manner, a discharge state between discharge electrode 12 a andinduction electrode 12 b is stabilized, and both positive and negativeions or negative ions can suitably be generated.

A discharge electrode contact 12 e is electrically connected todischarge electrode 12 a via a connection terminal 12 c provided on thesurface where discharge electrode 12 a is located. One end of aconductive lead is connected to discharge electrode contact 12 e whilethe other end thereof is connected to voltage application circuit 20, sothat discharge electrode 12 a and voltage application circuit 20 canelectrically be connected. An induction electrode contact 12 f iselectrically connected to induction electrode 12 b via a connectionterminal 12 d provided on the surface where induction electrode 12 b islocated. One end of a lead implemented by a copper wire is connected toinduction electrode contact 12 f while the other end thereof isconnected to voltage application circuit 20, so that induction electrode12 b and voltage application circuit 20 can electrically be connected.

FIG. 8 is a circuit diagram of voltage application circuit 20 in thefirst embodiment. Referring to FIG. 8, voltage application circuit 20includes an AC power supply 201, a switching transformer 202, a switchrelay 203, a resistor 204, diodes 205 a to 205 d, a capacitor 206, andan SIDAC (R) 207. SIDAC (R) 207 is one type of silicon control rectifierSCR and manufactured by Shindengen Electric Manufacturing Co., Ltd.

One end of AC power supply 201 is connected to the anode of diode 205 aand the cathode of diode 205 c, while the other end thereof is connectedto a common terminal 203 a of switch relay 203. The cathode of diode 205a is connected to one end of resistor 204 and the cathode of diode 205d. The other end of resistor 204 is connected to one end of a primarycoil L1 of transformer 202 and one end of capacitor 206. The other endof primary coil L1 is connected to the anode of SIDAC (R) 207. The otherend of capacitor 206 is connected to the cathode of SIDAC (R) 207, ofwhich connection node is connected to one selection terminal 203 b inswitch relay 203 and respective anodes of diodes 205 b and 205 c. Thecathode of diode 205 b is connected to the anode of diode 205 d, ofwhich connection node is connected to the other selection terminal 203 cof switch relay 203. One end of a secondary coil L2 of transformer 202is connected to discharge electrode contact 12 e of ion generator 10,while the other end thereof is connected to a common terminal 208 a of arelay 208. One selection terminal 208 c in relay 208 is connected to theanode of a diode 209, and the cathode of diode 209 is connected toinduction electrode contact 12 f Induction electrode contact 12 f of iongenerator 10 is connected to the other selection terminal 208 b in relay208 and the anode of diode 209.

In voltage application circuit 20 configured as described above, whenair conditioning apparatus 100 is not in the prediction purificationmode and when the drive mode of ion generator 10 is set to the cleanmode, selection terminal 203 b is selected in switch relay 203 andselection terminal 208 b is selected in switch relay 208.

Here, an output voltage of AC power supply 201 is subjected to half-waverectification in diode 205 a, then lowered by resistor 204, and appliedto capacitor 206. When capacitor 206 is charged and a voltage across thecapacitor attains a prescribed threshold value, SIDAC (R) 207 attains anon state and the charged voltage of capacitor 206 is discharged.Accordingly, a current flows through primary coil L1 in transformer 202to transmit energy to secondary coil L2, whereby a pulse voltage isapplied to ion generator 10. Immediately thereafter, SIDAC (R) 207attains an off state and charge of capacitor 206 is started again.

By repeating charge and discharge described above, an AC impulse voltagein FIG. 9A (pp (Peak-to-Peak) value: 3.5 [kV], the number of times ofdischarge: 120 [times per second], for example) is applied betweendischarge electrode 12 a and induction electrode 12 b of ion generator10. Here, corona discharge occurs in the vicinity of ion generator 10,and the ambient air is ionized. That is, H⁺(H₂O)_(m) which is a positiveion is generated when a positive voltage is applied, while O₂ ⁻(H₂O)_(n)which is a negative ion is generated when a negative voltage is applied(m, n are 0 or any natural number). More specifically, the AC voltage isapplied between discharge electrode 12 a and induction electrode 12 b ofion generator 10. Then, oxygen or moisture in the air is energized byelectrolytic dissociation and ionized, whereby ions mainly containingH⁺(H₂O)_(m) (m is 0 or any natural number) and O₂ ⁻(H₂O)_(n) (n is 0 orany natural number) are generated. H⁺(H₂O)_(m) and O₂ ⁻(H₂O)_(n) areemitted to the space by means of the fan or the like and adhere to thesurface of airborne fungi, followed by chemical reaction. As a result ofchemical reaction, H₂O₂ or .OH which is an active species is generated.As H₂O₂ or OH exhibits extremely strong activity, airborne fungi in theair are enclosed and inactivated. Here, .OH is a type of active speciesand represents radical OH.

Positive and negative ions chemically reacts on the surface of cells ofthe airborne fungi, as shown in expressions (1) to (3), resulting ingeneration of hydrogen peroxide (H₂O₂) or hydroxyl radical (.OH) whichis active species. In expressions (1) to (3), m, m¹, n, and n¹ represent0 or any natural number respectively.

In this manner, airborne fungi are destroyed by a decomposition actionof the active species. Therefore, the fungi floating in the air canefficiently be inactivated and eliminated.H₃O⁺(H₂O)_(m)+O₂ ⁻(H₂O)_(n)→.OH+½O ₂+(m+n+1)H₂O   (1)H₃O⁺(H₂O)_(m)+H₃O⁺(H₂O)_(m′)+O₂ ⁻(H₂O)_(n)+O₂⁻(H₂O)_(n′)→2.OH+O₂+(m+m′+n+n′+2)H₂O   (2)H₃O⁺(H₂O)_(m)+H₃O⁺(H₂O)_(m′)+O₂ ⁻(H₂O)_(n)+O₂⁻(H₂O)_(n′)→H₂O₂+O₂+(m+m′+n+n′+2)H₂O   (3)

According to a mechanism described above, an effect to inactivateairborne fungi or the like can be obtained through emission of positiveand negative ions shown above.

In addition, according to the expressions (1) to (3) above, the sameaction can also be achieved on a surface of a toxic substance in theair. Therefore, hydrogen peroxide (H₂O₂) or hydroxyl radical (.OH) whichis active species oxidizes or decomposes the toxic substance, andtransforms a chemical substance such as formaldehyde or ammonia to aharmless substance such as carbon dioxide, water or nitrogen, therebyrendering the toxic substance substantially harmless.

By driving the blower fan, positive and negative ions generated by iongenerator 10 can be emitted outside the main unit. An action of suchpositive and negative ions can inactivate molds and fungi in the air andsuppress proliferation thereof

In addition, the positive and negative ions also serve to inactivateviruses such as coxsackie virus or polio virus, thereby preventingimpureness due to introduction of these viruses. Further, as it has beenconfirmed that the positive and negative ions serve to decomposemolecules causing odor, the positive and negative ions can be utilizedfor deodorization of a space.

Wind was generated toward ion generator 10 by a not-shown fan, and anamount of positive ions and negative ions that arrived at an ion counterpositioned approximately 25 cm away from ion generator 10 was measuredrespectively. At the ion counter, approximately three hundred thousandpositive ions and negative ions were measured respectively.

On the other hand, when air conditioning apparatus 100 is in theprediction purification mode, the drive mode of ion generator 10 is setto the clean mode without exception. Here, selection terminal 203 c isselected in switch relay 203, while selection terminal 208 b is selectedin switch relay 208.

Accordingly, the output voltage of AC power supply 201 is subjected tofull-wave rectification in a diode bridge constituted of diodes 205 a to205 d, then lowered by resistor 204, and applied to capacitor 206.Therefore, an AC impulse voltage of discharge frequency higher than whennot in the prediction purification mode (pp value: 3.5 [kV], the numberof times of discharge: 240 [times per second], for example) is appliedbetween discharge electrode 12 a and induction electrode 12 b of iongenerator 10, as shown in FIG. 9B.

Here, an amount of ions was measured under the condition describedabove. As a result, at the ion counter, approximately five hundredthousand positive ions and negative ions per cc were measuredrespectively. That is, an amount of ions 1.7 times as large as when notin the prediction purification mode was measured.

An operation the same as described above can be achieved also when theconnection node of the cathode of diode 205 b and the anode of diode 205d is connected to the other end of AC power supply 201 instead of switchrelay 203, a switch is connected in series to the anode or the cathodeof diode 205 c or diode 205 d, and the switch is controlled inaccordance with the drive mode.

In addition, when ion generator 10 is in the ion control mode, selectionterminal 203 b is selected in switch relay 203, while selection terminal208 c is selected in switch relay 208.

As described above, as half-wave rectification is carried out by diode209, solely a pulse of the negative voltage among the voltageapplication pulses shown in FIG. 9A is applied to ion generator 10.Consequently, corona discharge occurs in the vicinity of ion generator10, and the ambient air is ionized. Here, as solely the negative voltageis applied, O₂ ⁻(H₂O)_(n) which is negative ion is generated.

<First Variation of Voltage Application Circuit>

FIG. 10 is a circuit diagram of a variation of the voltage applicationcircuit. Referring to FIG. 10, the voltage application circuit here isdifferent from voltage application circuit 20 in FIG. 8 in a circuitconfiguration between AC power supply 201 and primary coil L1 inswitching transformer 202. As other circuits are the same as in thefirst embodiment, description thereof will not repeated. One end of ACpower supply 201 is connected to one end of a resistor 214, while theother end of resistor 214 is connected the anode of a capacitor 215. Theother end of AC power supply 201 is connected to the cathode of SIDAC(R) 207, one end of capacitor 106 a, and one end of a switch 213. Thecathode of a diode 215 is connected to one ends of capacitors 206 a, 206b and primary coil L1. The other end of capacitor 206 b is connected tothe other end of switch 213.

In a voltage application circuit 20 a in the variation configured in theabove-described manner, when air conditioning apparatus 100 is not inthe prediction purification mode, relay 213 closes. The output voltageof AC power supply 201 is subjected to half-wave rectification in diode215, and thereafter applied to capacitors 206 a and 206 b. Whencapacitors 206 a and 206 b are charged and voltages across thecapacitors attain a prescribed threshold value, SIDAC (R) 207 attains anon state and the charged voltages of capacitors 206 a and 206 b aredischarged. Accordingly, a current flows through primary coil L1 intransformer 202 to transmit energy to secondary coil L2, whereby a pulsevoltage is applied to ion generator 10. Immediately thereafter, SIDAC(R) 207 attains an off state and charge of capacitors 206 a and 206 b isstarted again.

On the other hand, when air conditioning apparatus 100 is in theprediction purification mode, relay 213 opens. The output voltage of ACpower supply 201 is subjected to half-wave rectification in diode 215,and applied solely to capacitor 206 a. When capacitor 206 a is chargedand a voltage across the capacitor attains a prescribed threshold value,SIDAC (R) 207 attains an on state and the charged voltage of capacitor206 a is discharged. Accordingly, a current flows through primary coilL1 in transformer 202 to transmit energy to secondary coil L2, whereby apulse voltage is applied to ion generator 10. Immediately thereafter,SIDAC (R) 207 attains an off state and charge of capacitor 206 a isstarted again.

When switch 213 is open, the voltage applied to SIDAC (R) 207 attainsthe threshold value earlier than when it is closed. Therefore, thedischarge frequency of the voltage pulse applied to ion generator 10becomes higher when switch 213 is open than when it is closed. As thedischarge frequency of the pulse applied to ion generator 10 is higher,an amount of generated ions increases. Therefore, solely by switchingswitch 213, an amount of ions generated from ion generator 10 can beswitched.

FIGS. 11A and 11B show waveforms of voltages output from voltageapplication circuit 20 a in the variation. FIG. 11A shows a waveformwhen switch 213 is closed, and illustrates a waveform of a voltage thathas been subjected to half-wave rectification in diode 215 and awaveform of a voltage pulse applied to ion generator 10. FIG. 11Billustrates a waveform of a voltage that has been subjected to half-waverectification when switch 213 is open and a waveform of a voltage pulseapplied to ion generator 10

In voltage application circuit 20 described above, half-waverectification and full-wave rectification have been switched byswitching switch 203. Though solely an example of half-waverectification has been described with regard to voltage applicationcircuit 20 a in the variation, switching between full-wave rectificationand half-wave rectification may be employed. In such a case, when thevoltage pulse of low discharge frequency is applied to ion generator 10,the voltage that has been subjected to half-wave rectification is usedand switch 213 is closed. Meanwhile, when a voltage pulse of highdischarge frequency is applied to ion generator 10, full-waverectification is used and switch 213 is opened.

<Second Variation of Ion Generator and Voltage Application Circuit>

FIGS. 12A and 12B show variations of the ion generator in the firstembodiment. Referring to FIGS. 12A and 12B, an ion generator 10A in thisvariation is different from ion generator 10 described above in that itincludes a first discharge portion 21 constituted of a dischargeelectrode 21 a and an induction electrode 21 b, and a second dischargeportion 22 constituted of a discharge electrode 22 a and an inductionelectrode 22 b. In other words, ion generator 10A in this variation isdifferent in including two discharge portions 21 and 22.

In ion generator 10A in this variation, induction electrodes 21 b and 22b are formed on a surface of lower dielectric 11 b, while dischargeelectrodes 21 a and 22 a are formed on a surface of upper dielectric 11a. The surface of upper dielectric 11 a is covered with coating layer13. In addition, upper dielectric 11 a is stacked on the surface oflower dielectric 11 b where induction electrodes 21 b and 22 b areformed. Discharge electrode 21 a and induction electrode 21 b in firstdischarge portion 21 are arranged in positions opposing to each other,while discharge electrode 22 a and induction electrode 22 b in seconddischarge portion 22 are arranged in positions opposing to each other.

In the first discharge portion, connection terminal 21 e of dischargeelectrode 21 a is connected to discharge electrode contact 21 e, whichis connected to a voltage application circuit 20B via a lead. Inaddition, connection terminal 21 d of induction electrode 21 b isconnected to induction electrode contact 21 f, which is connected tovoltage application circuit 20B via a lead.

Similarly, in second discharge portion 22, connection terminal 22 c ofdischarge electrode 22 a is connected to discharge electrode contact 22e, which is connected to voltage application circuit 20B via a lead. Inaddition, connection terminal 22 d of induction electrode 22 b isconnected to induction electrode contact 22 f, which is connected tovoltage application circuit 20B via a lead.

FIG. 13 is a circuit diagram of voltage application circuit 20Bconnected to ion generator 10A in the variation. Referring to FIG. 13,voltage application circuit 20B includes AC power supply 201, atransformer 222, a switch relay 233, resistors 224, 225, diodes 226 to230, capacitors 231 a, 231 b, and an SIDAC (R) 232.

One end of AC power supply 201 is connected to the anode of diode 226via resistor 224. The cathode of diode 226 is connected to one end of afirst coil 222 a implementing a primary side of transformer 222, theanode of diode 227, and the anode of SIDAC (R) 232. The other end offirst coil 222 a is connected to the cathode of diode 227, of whichconnection node is connected to one ends of capacitors 231 a and 231 b.The cathode of SIDAC (R) 232, the other end of capacitor 231 a, and oneend 233 a of switch 233 are connected to one another, of whichconnection node is connected to the other end of AC power supply 201.The other end 233 b of switch 233 is connected to the other end ofcapacitor 231 b.

One end of a second coil 222 b implementing a secondary side oftransformer 222 is connected to discharge electrode contact 21 e offirst discharge portion 21, while the other end of second coil 222 b isconnected to induction electrode contact 21 f of first discharge portion21, the cathode of diode 229, and the anode of diode 230. The anode ofdiode 229 is connected to one selection terminal 223 a of switch relay223, and the cathode of diode 230 is connected to the other selectionterminal 223 b of switch relay 223. One end of a third coil 222 cimplementing a secondary side of transformer 222 is connected todischarge electrode contact 22 e of second discharge portion 22, whilethe other end of third coil 222 c is connected to induction electrodecontact 22 f of second discharge portion 22 and the anode of diode 228.A common terminal 223 c of switch relay 223 is connected to the cathodeof diode 228, of which connection node is connected to the other end ofAC power supply 201 via resistor 225.

In voltage application circuit 20B configured in the above-describedmanner, when air conditioning apparatus 100 is not in the predictionpurification mode and when the drive mode in ion generator 10 is set tothe clean mode, switch 233 closes and selection terminal 223 a isselected in switch relay 223. Here, a positive DC impulse voltage isapplied between discharge electrode 21 a and induction electrode 21 b infirst discharge portion 21, while a negative DC impulse voltage isapplied between discharge electrode 22 a and induction electrode contact22 b in second discharge portion 22. By application of such voltages,corona discharge occurs in the vicinity of first discharge portion 21and second discharge portion 22, and the ambient air is ionized. Here,H⁺(H₂O)_(m) which is a positive ion is generated in the vicinity offirst discharge portion 21 to which the positive DC impulse has beenapplied, whereas O₂ ⁻(H₂O)_(n) which is a negative ion is generated inthe vicinity of second discharge portion 22 to which the negative DCimpulse has been applied (m, n are 0 or any natural number).

In this manner, when selective terminal 223 a is selected in switchrelay 223, substantially the same amount of positive ions and negativeions can be generated from first discharge portion 21 and seconddischarge portion 22 respectively. Therefore, positive and negative ionsare caused to adhere to floating fungi or the like in the air, so thatfloating fungi can be eliminated with decomposition action of generatedhydrogen peroxide (H₂O₂) and/or hydroxyl radical (.OH) which is activespecies.

On the other hand, when air conditioning apparatus 100 operates in theprediction purification mode, switch 233 is opened and selectionterminal 223 a is selected in switch relay 223. In this case, solelycapacitor 231 a is charged. Therefore, a time period until the voltageapplied to SIDAC (R) 232 attains the prescribed threshold value isshortened. Accordingly, discharge frequencies of the positive DC impulsevoltage applied to first discharge portion 21 and the negative DCimpulse voltage applied to second discharge portion 22 are increased. Inthis manner, a larger amount of positive ions is generated in firstdischarge portion 21, and a larger amount of negative ions is generatedin second discharge portion 22.

When air conditioning apparatus 100 does not operate in the predictionpurification mode and when the drive mode of ion generator 10 is set tothe ion control mode, switch 233 is closed and selection terminal 22 bais selected in switch relay 223.

In such a case, the negative DC impulse voltage is applied to both firstdischarge portion 21 and second discharge portion 22. When such anegative DC impulse voltage is applied, O₂ ⁻(H₂O)_(n) which is anegative ion (n is 0 or any natural number) is generated in the vicinityof both first discharge portion 21 and second discharge portion 22.

As described above, when selection terminal 223 b is selected in switchrelay 223, solely negative ions can be generated from both firstdischarge portion 21 and second discharge portion 22. Therefore, ionbalance can be adjusted so as to create a state in which negative ionsare dominant, thereby enhancing relaxation effect.

A degree of impureness will now be described. FIG. 14 shows an exampleof a degree of impureness evaluation table used in air conditioningapparatus 100 in the first embodiment. The degree of impurenessevaluation table is stored in advance in a read-only memory (ROM) incontrol unit 150 in air conditioning apparatus 100.

Referring to FIG. 14, the degree of impureness evaluation tableassociates odor sensor output levels, dust sensor output levels andresults of addition of values from both sensors with the degree ofimpureness for storage. In the present embodiment, output levels of odorsensor 154 ranges from 0 to 3, while output levels of dust sensor 153ranges from 0 to 3. That is, an amount of odor and dust is expressed andoutput in 4 levels. As the value for odor sensor output level becomeslarger, it indicates that an amount of substances in the air causing theodor is larger. Meanwhile, an amount of dust in the air is larger, asthe value for dust sensor output level becomes larger. The additionresult represents the sum of the odor sensor output level and the dustsensor output level. The addition result ranges from 0 to 6.

The degree of impureness is associated with the odor sensor output leveland the dust sensor output level. Even when the addition results are thesame, the degree of impureness may be different. For example, when theodor sensor output level attains 1 and the dust sensor output levelattains 2, the addition result is 3 and this example is associated withthe degree of impureness of 1. On the other hand, when the odor sensoroutput level attains 3 and the dust sensor output level attains 0, thisexample is associated with the degree of impureness of 2 in spite of theaddition result of 3. This is because the odor sensor output levelattains 3, which indicates that a largest amount of substances causingodor is present. In such a case, the degree of impureness is determinedas 2, not 1.

In the drawing, a color on the clean sign indicator light corresponds tothe degree of impureness. That is, when the degree of impureness is 0,clean sign indicator light 114 illuminates in green. When the degree ofimpureness is 1, clean sign indicator light 114 illuminates in orange.When the degree of impureness is 2, clean sign indicator light 114illuminates in red. The undetected mode in the drawing refers to a modeset until the output levels of odor sensor 154 and dust sensor 153 arestabilized. During such a time period, the degree of impureness is notdetermined, and accordingly, it is referred to as “undetected mode”.Here, clean sign indicator light 114 illuminates in the order of green,orange and red, and thereafter illuminates in the order of red, orangeand green, which will be repeated. Clean sign indicator light 114illuminates sequentially in different colors, so that the user can benotified that the degree of impureness is not yet evaluated.

Though the degree of impureness has ranged in 3 levels from 0 to 2 here,the range is not limited to such an example. A larger or smaller numberof levels may be set, and two levels may be set, for example. Inaddition, though the degree of impureness has been detected based on theoutput values from two sensors of odor sensor 154 and dust sensor 153 inthe present embodiment, any one sensor output may be used to detect thedegree of impureness.

FIG. 15 is a flowchart illustrating a flow of an operation modedetermining process executed in air conditioning apparatus 100 in thefirst embodiment. The operation mode determining process is executed incontrol unit 150 of air conditioning apparatus 100. Referring to FIG.15, in the operation mode determining process, the degree of impurenessis detected based on output levels from dust sensor 153 and odor sensor154 (step S01), using the degree of impureness evaluation tabledescribed above. Then, based on the detected degree of impureness,whether or not the air in the room is impure (step S02). When the air inthe room is determined as impure, the process proceeds to step S03, andotherwise the process proceeds to step S08. Here, when the degree ofimpureness detected at step S01 attains at least 1, determination asimpure is made at step S02.

At next step S03, output values of temperature sensor 151 and humiditysensor 152 are obtained. At step S04, whether or not the obtained outputvalues of the temperature sensor and the humidity sensor are at least25° C. and at least 70% respectively is determined. When the outputvalues from the temperature sensor and the humidity sensor satisfy thecondition above, the process proceeds to step S06, and otherwise theprocess proceeds to step S05. At step S04, whether or not the air in theroom is in a state in which molds are likely to proliferate isdetermined. Therefore, the threshold values of the temperature and thehumidity are not limited to 25° C. and 70% respectively, and any valueclose to those may be accepted.

At step S05, whether or not the output values of the temperature sensorand the humidity sensor both obtained at step S03 are at most 18° C. andat most 40% respectively is determined. When the output values from thetemperature sensor and the humidity sensor satisfy the condition above,the process proceeds to step S06, and otherwise the process proceeds tostep S07. At step S05, whether or not the air in the room is in a statein which influenza viruses are likely to proliferate is determined.Therefore, the threshold values of the temperature and the humidity arenot limited to 18° C. and 40% respectively, and any value close to thosemay be accepted.

At step S06, the operation mode of air conditioning apparatus 100 is setto the prediction purification mode and the clean mode. Accordingly, alarge amount of positive and negative ions is generated from iongenerator 10. Here, on display portion 103, prediction purificationindicator light 113 illuminates and cluster ion indicator light 115illuminates in blue.

On the other hand, at step S07, the prediction purification mode is notset and solely the clean mode is set. Accordingly, a normal amount ofpositive and negative ions is generated from ion generator 10, whichamount is smaller than in the operation mode set at step S06. Here, ondisplay portion 103, prediction purification indicator light 113 turnsoff and cluster ion indicator light 115 illuminates in blue.

When the air in the room has been determined as clean at step S02, theprocess proceeds to step S08. At step S08, output values fromtemperature sensor 151 and humidity sensor 152 are obtained. The processin this step is similar to that in step S03.

The process in step S09 is similar to that in step S04. That is, whetheror not the temperature is at least 25° C. and the humidity is at least70% is determined, using the output values from temperature sensor 151and humidity sensor 152 obtained at step S08. When the temperature andthe humidity satisfy the condition, the process proceeds to step S11,and otherwise the process proceeds to step S10.

The process in step S10 is similar to that in step S05 described above.When the conditions of the temperature of at most 18° C. and thehumidity of at most 40% are satisfied, the process proceeds to step S11,and otherwise the process proceeds to step S12.

At step S11, the operation mode of air conditioning apparatus 100 is setto the prediction purification mode and also to the clean mode. Thisoperation mode is the same as in step S06. In such an example, the airin the room is either in a state in which molds are likely toproliferate or a state in which influenza viruses are likely toproliferate. Here, positive and negative ions are generated from iongenerator 10, and an amount thereof is increased as compared with thenormal amount.

On the other hand, at step S12, the operation mode of air conditioningapparatus 100 is set to the ion control mode. When the process proceedsto step S12, the air in the room is clean and not in the state in whichmolds or influenza viruses are likely to proliferate. As a probabilityof presence of molds or influenza viruses in the air in the room is low,ion generator 10 generates not positive and negative ions but negativeions in an amount larger than positive ions. Here, on display portion103, prediction purification indicator light 113 turns off and clusterion indicator light 115 illuminates in green.

Control unit 150 controls voltage driving circuit 20 in accordance withrespective operation modes at steps S06, S07, S11, and S12. Controlledby control unit 150, voltage driving circuit 20 applies a drivingvoltage determined in accordance with the operation mode to iongenerator 10.

Ion generator 10 generates a large amount of ions when the voltage pulseof high discharge frequency is applied thereto. In addition, an amountof positive and negative ions generated from ion generator 10 can becontrolled also by varying a duty ratio of the applied voltage pulse.Under the condition that the cycle of the applied voltage pulse isconstant, an amount of generated ions from ion generator 10 is largerwhen the duty is set to 100% than when it is set to 50%. Voltage drivingcircuit 20 can control an amount of positive and negative ions generatedfrom ion generator 10 by varying the duty.

FIG. 16 shows a relation between the operation mode of air conditioningapparatus 100 and a fan motor output and a voltage applied to iongenerator 10 in the first embodiment. Here, the voltage applied to iongenerator 10 when the duty is varied is shown. Referring to FIG. 16, •represents examples in which the operation mode is set to the predictionpurification mode, while x represents examples in which the operationmode is not set to the prediction purification mode. In addition, afield of the ion mode includes the clean mode and the ion control mode.That is, in air conditioning apparatus 100 in the present embodiment,the operation mode includes three modes: the clean mode not in theprediction purification mode; the clean mode in the predictionpurification mode; and the ion control mode not in the predictionpurification mode.

When the operation mode is set to the prediction purification mode, theair in the room may be in the first state in which molds are likely toproliferate or in the second state in which influenza viruses are likelyto proliferate. The clean mode is different from the ion control mode inthat positive and negative ions are generated from ion generator 10 inthe clean mode and that negative ions are generated from ion generator10 in an amount larger than that of positive ions in the ion controlmode. If the operation mode is set not only to the clean mode but alsoto the prediction purification mode, an amount of generated positive andnegative ions is larger than when the prediction purification mode isnot set.

It is noted that an amount of ions generated from ion generator 10 inthe present embodiment refers to a ratio of positive ions to negativeions in the air, and relates to the fan motor output. Here, the fanmotor output is indicated by the volume of air, which is categorized in6 levels from fan level 1 to 6. Fan speed is larger at fan level 6 thanat fan level 1.

When an applied voltage duty increases, generated discharge noise alsobecomes greater. Accordingly, when the fan motor output is small andwind noise is small, the discharge noise from the ion generator ispreferably small. Therefore, by changing the applied voltage duty inaccordance with the fan motor output, silent operation of an entireproduct can be realized.

When the wind speed is low, an amount of air flowing over ion generator10 becomes smaller. Accordingly, even if an actual amount of ionized airis small in ion generator 10, ion concentration becomes higher.Therefore, the ion concentration at fan level 1 and duty 20% is higherthan that at fan level 6 and duty 50%. That is, the ion concentration atfan level 1 and duty 20% in the prediction purification mode is higherthan that at fan level 6 and duty 50% when not in the predictionpurification mode but in the clean mode. Thus, an amount of generatedions in the prediction purification mode is larger than that when not inthe prediction purification mode.

When the wind speed is low, the wind noise is also small. In order tolower overall operation noise, the discharge noise from the iongenerator and the voltage duty are preferably small. In contrast, whenthe wind speed is high, the wind noise is also great. Therefore, even ifthe discharge noise from the ion generator is great, it does notconsiderably affect the overall operation noise. Therefore, by settingduty 100% at fan level 5 or 6, quietness and desired ion concentrationcan be realized without much affecting the overall operation noise.

FIG. 16 also shows a manner of indication on cluster ion indicator light115 in accordance with respective modes. Specifically, in the clean modenot in the prediction purification mode, cluster ion indicator light 115illuminates in blue. In addition, in the clean mode and the predictionpurification mode, cluster ion indicator light 115 slowly repeatsflashing in blue in a cycle of 5 seconds. When flashing of cluster ionindicator light 115 in blue is observed, the operation is in theprediction purification mode.

When air conditioning apparatus 100 is not in the predictionpurification mode but in the ion control mode, cluster ion indicatorlight 115 illuminates in green.

As described above, in air conditioning apparatus 100 in the presentembodiment, positive and negative ions in an amount larger than normalare generated when the air in the room is in the state in which moldsare likely to proliferate (YES at step S04 or S09) or in the state inwhich influenza viruses are likely to proliferate (YES at step S05 orS10). Therefore, in the state in which fungi such as molds or influenzaviruses are likely to proliferate, a large amount of positive andnegative ions is generated so as to enhance an effect to kill fungi suchas molds and influenza viruses.

In addition, in air conditioning apparatus 100 in the presentembodiment, ion generator 10 generates a normal amount of positive andnegative ions, when the air in the room is not in the state in whichmolds are likely to proliferate (NO at step S04) but in the state inwhich influenza viruses are less likely to proliferate (NO at step S05).Therefore, even when the air in the room is not in the state in whichairborne fungi are likely to proliferate, airborne fungi can be killed.Namely, the airborne fungi can further be killed. In addition, since thevoltage pulse of low discharge frequency or the pulse of small duty isapplied to ion generator 10, power consumption is reduced and thedischarge noise is suppressed.

Moreover, when the air in the room is clean (NO at step S02) and whenthe air in the room is in the state in which molds are unlikely toproliferate (NO at step S09) and in the state in which influenza virusesare unlikely to proliferate (NO at step S11), ion generator 10 is set tothe ion control mode in which negative ions in an amount larger thanthat of positive ions are generated. Accordingly, as the concentrationof negative ions is increased in the room, refreshing effect isachieved. In this manner, when the air in the room is clean and in anenvironment in which airborne fungi are less likely to proliferate, anenvironment comfortable for humans can be created.

In addition, the operation mode of air conditioning apparatus 100 in thepresent embodiment is set to the clean mode (step S06 or S07) when theair in the room is impure (YES at step S02). Accordingly, positive andnegative ions are generated from ion generator 10. When the air in theroom is impure, it is probable that airborne fungi are contained.Therefore, by generating both positive and negative ions, airborne fungiin the air can efficiently be killed.

When the air in the room is impure (YES at step S02) and in the state inwhich molds are likely to proliferate (YES at step S04) or in the statein which influenza viruses are likely to proliferate (YES at step S05),an amount of generated positive and negative ions is increased.Accordingly, when the room is in the state in which molds are likely toproliferate or in the state in which influenza viruses are likely toproliferate, an amount of generated positive and negative ions isincreased, so as to efficiently kill airborne fungi. Moreover, as thevoltage pulse of high discharge frequency or of large duty is applied toion generator 10 solely in the prescribed state, it is not necessary toalways apply the voltage pulse of high discharge frequency or of largeduty. That is, power consumption in ion generator 10 can be reduced.Further, when the voltage pulse of high discharge frequency is applied,ion generator 10 produces noise greater than when the voltage pulse oflow discharge frequency is applied. As described above, since thevoltage pulse of high discharge frequency is applied solely in theprescribed state, the noise can be minimized.

When the voltage pulse of high discharge frequency or of large duty isapplied, ion generator 10 experiences faster deterioration than when thevoltage pulse of low discharge frequency or of small duty is applied.Accordingly, since the voltage pulse of high discharge frequency or oflarge duty is not always applied to ion generator 10, ion generator 10can be used for a long period of time.

Though air conditioning apparatus 100 with ion generator 10 has beendescribed in the present embodiment, ion generator 10 may be applied toa dehumidifier attaining a dehumidifying function. The dehumidifiercarries out dehumidification when the humidity in the room increases, soas to maintain the humidity in the room to a prescribed level.Accordingly, if the humidity in the room is adjusted so as to attain thestate in which molds are less likely to proliferate or so as to maintainthe humidity at which influenza viruses are less likely to proliferate,effects from dehumidification of the air by means of the dehumidifierand the positive and negative ions generated by ion generator 10 arecombined to attain the state of the air in the room in which molds areless likely to proliferate or the state in which influenza viruses areless likely to proliferate. Even if the room is in the state in whichmolds are likely to proliferate, proliferation thereof can be preventedby dehumidification by means of the dehumidifier, and molds canefficiently be killed by virtue of the positive and negative ionsgenerated by ion generator 10.

Note that a humidifier attaining a humidifying function may be employedinstead of the dehumidifier. Unlike the dehumidifier, the humidifierincreases the humidity in the room. Therefore, when the humidity in theroom is lowered and the room is in the state in which influenza virusesare likely to proliferate, humidification by means of the humidifier iscarried out and an environment in which influenza viruses are lesslikely to proliferate is achieved. Thus, proliferation of the virus isprevented, and influenza viruses can efficiently be killed by virtue ofthe positive and negative ions generated by ion generator 10.

Furthermore, ion generator 10 may be applied to an air conditionerattaining a function to cool or warm the air in the room. The airconditioner can warm or cool the air in the room, so as to set atemperature at which molds are less likely to proliferate or so as toadjust the temperature in the room to a level at which influenza virusesare less likely to proliferate. Therefore, even if the room is in thestate in which molds or viruses are likely to proliferate, thetemperature is adjusted by cooling/warming function, thereby attainingan environment in which molds or influenza viruses are less likely toproliferate. Thus, proliferation of the molds and viruses is prevented,and the molds and the influenza viruses can efficiently be killed byvirtue of the positive and negative ions generated by ion generator 10.

In addition, ion generator 10 may be applied to an air conditionerimplemented by a combination of a dehumidifier, a humidifier, a heater,and a cooler.

In the present embodiment, the prescribed state has been defined as thestate of the air in the room determined by the temperature and thehumidity, including the first state determined by the temperature andthe humidity at which molds are likely to proliferate and the secondstate determined by the temperature and the humidity at which virusesare likely to proliferate. In addition, the first state has been definedas the state of the temperature and the humidity of at least 25° C. andat least 70% respectively, while the second state has been defined asthe state of the temperature and the humidity of at most 18° C. and atmost 40% respectively. The first and the second states, however, are notlimited to such an example. The first state may be any state determinedby the temperature and the humidity at which molds are likely toproliferate, and the second state may be any state determined by thetemperature and the humidity at which viruses such as influenza virusesare likely to proliferate.

FIG. 17 shows one example of the prescribed state. Referring to FIG. 17,the ordinate represents the temperature, while the abscissa representsthe humidity, so as to show a region determined by the temperature andthe humidity. The first state includes a region defined by thetemperature of at least 13° C. and the humidity of at least 70%. Thesecond state includes a region defined by the temperature of at most 13°C. and the humidity from at least 0% to at most 100%, a region definedby the temperature from at least 13° C. to at most 24° C. and thehumidity from at least 0% to at most 40%, and a region defined by thetemperature from at least 24° C. to at most 34° C. and the humidity fromat least 0% to at most 25%.

Accordingly, the first state includes a region defined by thetemperature of at least 25° C. (first temperature) and the humidity ofat least 70% (first humidity). In addition, the second state includes aregion defined by the temperature of at most 18° C. (second temperature)and the humidity of at most 40% (second humidity). The secondtemperature is lower than the first temperature, while the secondhumidity is lower than the first humidity.

When the prescribed state shown in FIG. 17 is used, in the operationmode determining process shown in FIG. 15, whether or not the air in theroom determined by the temperature and the humidity is in the firststate is determined at step S04 or S09. When the air in the room is inthe first state, determination as “true” is made, and otherwisedetermination as “false” is made. In addition, whether or not the air inthe room determined by the temperature and the humidity is in the secondstate is determined at step S05 or S10. When the air in the room is inthe second state, determination as “true” is made, and otherwisedetermination as “false” is made.

Second Embodiment

In air conditioning apparatus 100 in the first embodiment describedabove, when the operation mode determining process shown in FIG. 15 isexecuted, whether or not the prediction purification mode is to be sethas automatically been determined. In an air conditioning apparatus 100Ain the second embodiment, however, whether or not the operation mode isset to the prediction purification mode can be selected by the user.Accordingly, air conditioning apparatus 100A in the second embodimentincludes a prediction purification mode operation switch for switchingthe operation mode to the prediction purification mode. Moreover, airconditioning apparatus 100A in the second embodiment attains a functionto notify the user that the air in the room is in a state suitable foroperation in the prediction purification mode. In the following,differences from air conditioning apparatus 100 in the first embodimentwill be described.

FIGS. 18A and 18B shows appearance of air conditioning apparatus 100A inthe second embodiment. Second air conditioning apparatus 100A includes anotification light 301 in an upper portion of central panel 102 and aprediction purification mode operation switch 303 on top panel 104.

Notification light 301 illuminates or flashes when the air in the roomis in the first state or in the second state described above. With thislight, the user can be notified that the air in the room is in the firststate or in the second state. Note that notification light 301 may be adisplay device such as a liquid crystal display device, the cathode raytube (CRT) or electroluminescence, or a sound output device such as aspeaker or a buzzer. Alternatively, a combination of the display deviceand the sound output device may be employed. When the display device isused, a message such as “molds are likely to proliferate” or “virusesare likely to proliferate” may be displayed in order to indicate thatthe air in the room is in the first state or in the second state.Moreover, a message such as “press the prediction purification modeoperation switch” may be displayed in order to urge manipulation of theprediction purification mode operation switch. When the sound outputdevice is used, the message described above may be output as sound, oralternatively an alarm (including melody) may be output. Notificationlight 301 may be provided also in remote controller 130, in addition toin air conditioning apparatus 100A.

Prediction purification mode operation switch 303 serves as an inputswitch for accepting manipulation by the user when the air in the roomis in the first state or in the second state. When manipulation by theuser is accepted, air conditioning apparatus 100A starts operation inthe prediction purification mode. Prediction purification mode operationswitch 303 may be provided also in remote controller 130, in addition toin air conditioning apparatus 100A.

FIG. 19 is a flowchart illustrating a flow of an operation modedetermining process executed in air conditioning apparatus 100A in thesecond embodiment. The operation mode determining process is executed incontrol unit 150 of air conditioning apparatus 100A. The operation modedetermining process shown in FIG. 19 is different from that executed inair conditioning apparatus 100 in the first embodiment shown in FIG. 15in that new steps S05A and S05B are added between step S05 and step S06and that new steps S10A and S10B are added between step S10 and stepS11. As the processes from step S01 to step S05 and from step S08 tostep S10 are the same as described with reference to FIG. 15,description thereof will not be repeated.

If determination as YES is made at step S04 or S05, the process proceedsto step S05A. In other words, the process proceeds to step S05A when thestate of the air in the room determined by the temperature and thehumidity is in the first state or in the second state.

At step S05A, notification light 301 illuminates or flashes. In thismanner, the user is notified that the air in the room is in the firststate or in the second state.

At next step S05B, whether or not prediction purification mode operationswitch 303 has been manipulated by the user is determined. Ifmanipulation by the user is detected, the process proceeds to step S06,and otherwise the process proceeds to step S07.

On the other hand, if determination as YES is made at step S09 or S10,the process proceeds to step S10A. In other words, the process proceedsto step S10A when the state of the air in the room determined by thetemperature and the humidity is in the first state or in the secondstate.

The process at step S10A is the same as that at step S05A. That is,notification light 301 illuminates or flashes. In this manner, the useris notified that the air in the room is in the first state or in thesecond state.

Next step S10B is the same as that at step S05B. That is, whether or notprediction purification mode operation switch 303 has been manipulatedby the user is determined. If manipulation by the user is detected, theprocess proceeds to step S11, and otherwise the process proceeds to stepS12.

In this manner, in the air conditioning apparatus in the secondembodiment, notification light 301 illuminates or flashes. Thus, theuser is notified that the air in the room is in the first state or inthe second state. Then, after an instruction by the user throughprediction purification mode operation switch 303, the operation mode isset to the prediction purification mode and also to the clean mode. Whenthe operation mode is set to the prediction purification mode, positiveand negative ions in an amount larger than normal are generated from iongenerator 10. In addition, on display portion 103, predictionpurification indicator light 113 illuminates and cluster ion indicatorlight 115 illuminates in blue.

As described above, in air conditioning apparatus 100A in the secondembodiment, when the air in the room is in the first state or in thesecond state, the operation mode is set to the prediction purificationmode and the clean mode after the instruction by the user arrives. Whenthe operation mode of air conditioning apparatus 100A is set to theprediction purification mode and the clean mode, power consumption byion generator 10 is larger than in other operation mode. In addition,large noise is generated, and deterioration is faster. Therefore, theoperation mode of air conditioning apparatus 100A is set to theprediction purification mode when the user desires. Accordingly, theuser can select between lower power consumption, silent operation andlonger life cycle of ion generator 10 and prevention of proliferation ofmolds or viruses.

In air conditioning apparatus 100, 100A in the first or secondembodiment, when the operation mode is set to the predictionpurification mode and the clean mode, that is, when the air in the roomis in the first state or in the second state (in air conditioningapparatus 100A in the second embodiment, when the user provides aninstruction), an amount of ions generated from ion generator 10 islarger than in other operation mode. Alternatively, when the operationmode is set to the prediction purification mode and the clean mode, iongenerator 10 is driven so as to generate ions, whereas in otheroperation mode (normal state), ion generator 10 is not driven so as notto generate ions. In such a case, ions are generated only when the airin the room is in the first or second state (in air conditioningapparatus 100A in the second embodiment, when the user provides aninstruction). Therefore, airborne fungi can efficiently be killed. Inaddition, ion generator 10 needs to be driven only when the air in theroom is in the state in which airborne fungi are likely to proliferate.Accordingly, drive control of ion generator 10 is facilitated, powerconsumption is lowered, silent operation is set, and the life cycle ofion generator 10 can be extended.

Although the present invention has been described and illustrated indetail, it is clearly understood that the same is by way of illustrationand example only and is not to be taken by way of limitation, the spiritand scope of the present invention being limited only by the terms ofthe appended claims.

1. An ion generator, comprising: ion generation means for generatingions; temperature and humidity detection means for detecting atemperature and a humidity in a room; and control means for controllingsaid ion generation means so as to generate a larger amount of ions thanin a normal state when a state of the room detected by said temperatureand humidity detection means attains a prescribed state; wherein saidprescribed state includes a first state at a temperature and a humidityequal to or higher than a first temperature and a first humidityrespectively, and a second state at a temperature and a humidity equalto or lower than a second temperature and a second humidityrespectively, said second temperature is lower than said firsttemperature, and said second humidity is lower than said first humidity.2. The ion generator according to claim 1, further comprising: statenotification means for notification of said temperature detection resultand/or said humidity detection result; and instruction accepting meansfor accepting an instruction to start control of said ion generationmeans; wherein control of said ion generation means is started inresponse to acceptance of the instruction by said instruction acceptingmeans.
 3. (canceled)
 4. The ion generator according to claim 1, whereinsaid ion generation means generates positive ions and negative ions. 5.(canceled)
 6. (canceled)
 7. (canceled)
 8. The ion generator according toclaim 1, wherein said first state refers to a state in which thetemperature detected by said temperature and humidity detection means isat least 25° C. and the humidity detected by said temperature andhumidity detection means is at least 70%, and said second state refersto a state in which the temperature detected by said temperaturedetection means is at most 18° C. and the humidity detected by saidhumidity detection means is at most 40%.
 9. (canceled)
 10. (canceled)11. The ion generator according to claim 1, further comprisingimpureness detection means for detecting impureness in the room, whereinsaid control means causes said ion generation means to generate negativeions more than positive ions, when a state of the room detected by saidtemperature and humidity detection means does not attain said prescribedstate and when a prescribed degree of impureness is not detected by saidimpureness detection means.
 12. The ion generator according to claim 11,wherein said impureness detection means includes a dust sensor.
 13. Theion generator according to claim 11, wherein said impureness detectionmeans includes an odor sensor.
 14. An ion generator, comprising: iongeneration means for generating ions; impureness detection means fordetecting impureness in a room; temperature and humidity detection meansfor detecting a temperature and a humidity in the room; and controlmeans for controlling an amount of ions generated by said ion generationmeans, when a state of the room detected by said impureness detectionmeans and said temperature and humidity detection means attains aprescribed state; wherein said prescribed state includes a first stateat a temperature and a humidity equal to or higher than a firsttemperature and a first humidity respectively, and a second state at atemperature and a humidity equal to or lower than a second temperatureand a second humidity respectively, said second temperature is lowerthan said first temperature, and said second humidity is lower than saidfirst humidity.
 15. (canceled)
 16. The ion generator according to claim14, wherein said control means causes said ion generation means togenerate negative ions more than positive ions, when a degree ofimpureness detected by said impureness detection means does not attain aprescribed value and when a state of the room detected by saidtemperature and humidity detection means does not attain said prescribedstate.
 17. The ion generator according to claim 14, wherein saidimpureness detection means includes a dust sensor.
 18. The ion generatoraccording to claim 14 or 17, wherein said impureness detection meansincludes an odor sensor.
 19. An air conditioning apparatus, comprising:cleaning means for lowering a degree of impureness in a room; and theion generator according to claim 1 or
 14. 20. An air conditioningapparatus, comprising: dehumidifying and humidifying means for adjustinga humidity in a room; and the ion generator according to claim 1 or 14.21. An air conditioning apparatus, comprising: cooling and heating meansfor adjusting a temperature in a room; and the ion generator accordingto claim 1 or
 14. 22. An air conditioning apparatus, comprising: dustdetection means for detecting dust in a room; odor detection means fordetecting odor in the room; temperature detection means for detecting atemperature; and humidity detection means for detecting a humidity;characterized by control for purifying air based on said dust detectionmeans, said odor detection means, said temperature detection means, andsaid humidity detection means.
 23. An air conditioning apparatus,comprising: dust detection means for detecting dust in a room; odordetection means for detecting odor in the room; temperature detectionmeans for detecting a temperature; and humidity detection means fordetecting a humidity; characterized by purification of air in the roomin accordance with a value detected by said detection means.
 24. An airconditioning apparatus, comprising: dust detection means for detectingdust in a room; odor detection means for detecting odor in the room; andtemperature and humidity detection means for detecting a temperature anda humidity in the room; wherein when a state of the room detected bysaid dust detection means, said odor detection means and saidtemperature and humidity detection means attains a prescribed state, anoperation mode of means for purifying air in the room is switched fromlow to high such that performance thereof is improved.
 25. The airconditioning apparatus according to claim 24, wherein said prescribedstate includes a first state at a temperature and a humidity equal to orhigher than a first temperature and a first humidity respectively, and asecond state at a temperature and a humidity equal to or lower than asecond temperature and a second humidity respectively.
 26. The airconditioning apparatus according to claim 24, wherein when a valuedetected by said dust detection means and said odor detection means doesnot attain a prescribed value and when a state of the room detected bysaid temperature and humidity detection means does not attain saidprescribed state, the operation mode of the means for purifying the airin the room is not switched.